ACKNOWLEDGMENTS \\houw33883\sstaffor$\temporary\welding inspection\_toc.doc Welding Inspection Handbook ACK 1 Considerable data are presented in this Handbook, summarizing various Code topics. If this Handbook results in the better training of welding inspection personnel to the Code information presented herein, it will have served its purpose. As explained in the Commentary, portions of the referenced codes are verbatim excerpts. Selected figures and tables have been reproduced in their entirety. In each instance, the code paragraph or reference has been cited. The following Codes granted permission to use their publications as they are presented in this handbook for the original issue: American Welding Society: AWS D1.1, Structural Welding Code – Steel AWS A3.0, Welding Terms and Definitions American Society of Mechanical Engineers: ASME Section III, Nuclear Power Plant Components, Division I ASME Section IX, Welding and Brazing Qualificatibns American National Standards Institute: ASME B31.1, Power Piping Code The pictures and photographs used in Section 9, “Defects,” were provided through the courtesy of the Electric Power Research Institute (EPRI), Special Report entitled “NDE Characteristics of Pipe Weld Defects.”
DISCLAIMER NOTICE \\houw33883\sstaffor$\temporary\welding inspection\_toc.doc Welding Inspection Handbook Disclaimer 1 It should be understood by all persons using this handbook, that neither Bechtel Construction Operations, Inc, nor its related entities or their employees, agents or officers, give any warranties, express or implied, nor make any representations as to the accuracy, completeness or usefulness of the information or conclusions contained herein, nor assume any responsibility or liability of any nature from whatever cause including negligence resulting from the use of this Welding Inspection Handbook. Originally published as as noted: “© Welding Inspection Handbook, Revision 0, Bechtel Power Corporation, 1983, all rights reserved.” “© Welding Inspection Handbook, Revision 1, Bechtel Power Corporation, 1984, all rights reserved.” Additional copies of this handbook may be obtained by writing or telephoning
CONTENTS \\houw33883\sstaffor$\temporary\welding inspection\_toc.doc Welding Inspection Handbook Contents 1 Section Subject 1 SOCKET WELDS 2 MEASUREMENT OF FILLET WELDS 3 USE OF INSPECTION GAGES 4 GROOVE WELDS, AWS D1.1 (PIPE AND PLATE) 5 WELDING SYMBOLS (AWS A2.4) 6 VISUAL AND NDE ACCEPTANCE CRITERIA (AWS D1.1) 7 VISUAL AND NDE ACCEPTANCE CRITERIA (ASME/ANSI) 8 CODE REQUIRED NDE 9 DEFECTS 10 REPAIR OF WELD DEFECTS 11 BASE METAL REPAIR BY WELDING 12 WELDING PROCESSES 13 PREHEAT/INTERPASS TEMPERATURES 14 POSTWELD HEAT TREATMENT (PWHT) 15 PREQUALIFIED WELD JOINTS (AWS D1.1) 16 SKEWED T-JOINTS 17 PROCEDURE/WELDER QUALIFICATION (AWS D1.1) 18 PROCEDURE/WELDER QUALIFICATION (ASME SECTION IX) 19 CHARTS 20 TERMS AND DEFINITIONS
Section 1 Socket Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter01.doc Welding Inspection Handbook 1-0 Page 1.1 ASME B31.1 ............................................................................................. 1-1 1.1.1 Fittings....................................................................................................... 1-1 1.1.2 Flanges....................................................................................................... 1-2 1.2 ASME B31.3 ............................................................................................. 1-2 1.3 ASME SECTION III ................................................................................. 1-3 1.3.1 Welding Requirements ............................................................................... 1-3 1.4 AWS D1.1 ................................................................................................. 1-3 1.4.1 No Requirements in AWS D1.1.................................................................. 1-3
Section 1 Socket Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter01.doc Welding Inspection Handbook 1-1 1.1 ASME B31.1 In the assembly of the joint before welding, the pipe or tube shall be inserted into the socket to the maximum depth and then withdrawn approximately 1/16 inch from contact between the end of the pipe and the shoulder of the socket [See Figs 127.4.4 (B) and (C)]. In sleeve type joints without internal shoulder, there shall be a distance of approximately 1/16 inch between the butting ends of the pipe or tube. The fit between the socket and the pipe shall conform to applicable standards for socket weld fittings and in no case shall the inside diameter of the socket or sleeve exceed the outside diameter of the pipe or tube by more than 0.080 in. [127.3 (E)] 1.1.1 Fittings For socket welded fittings, the minimum welding dimensions are shown below. Figure 127.4.4 (C) Minimum Welding Dimensions Required for Socket Welding Components Other Then Flanges
Section 1 Socket Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter01.doc Welding Inspection Handbook 1-2 1.1.2 Flanges Typical welding details for slip-on and socket-welding flanges are shown below. Notes: (1) Refer to Para. 122.1.1 (F) for limitations of use. (2) Refer to Para. 122.1.1 (H) for limitations of use. (3) Refer to Para. 104.5.1 for limitations of use. Figure 127.4.4 (B) Welding Details for Slip-On and Socket-Welding Flanges; Some Acceptable Types of Flange Attachment Welds 1.2 ASME B31.3 Typical weld details for slip-on and socket weld flanges are shown in Figure 328.5.2B; minimum welding dimensions for other socket welding components are shown in Fig. 328.5.2C. (328.5.2(a) If slip-on flanges are single welded, the weld shall be at the hub. (328.5.2(b) Figure 328.5.2B Typical Details for Double Welded Slip-On and Socket Welding Flange Attachment Welds
Section 1 Socket Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter01.doc Welding Inspection Handbook 1-3 Figure 328.5.2C Minimum Welding Dimensions for Socket Welding Components Other Than Flanges 1.3 ASME SECTION III 1.3.1 Welding Requirements Illustrations concerning socket welds for ASME/ANSI-B31.1 and ASME Section III are the same. Also, the method used for calculation for determining socket weld size is the same, except that for flange-to-pipe socket weld requirements, the following apply. (NX-4427) (Figure NX-4427-1) 1.4 AWS D.1.1 1.4.1 No Requirements in AWS D1.1
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-0 Page 2.1 AWS D1.1 ................................................................................................. 2-1 2.1.1 Effective Length......................................................................................... 2-1 2.1.2 Effective Throat......................................................................................... 2-1 2.1.3 Theoretical Throat ..................................................................................... 2-2 2.1.4 Minimum Size............................................................................................ 2-3 2.1.5 Maximum Size Along Edges ...................................................................... 2-3 2.1.6 Minimum Length........................................................................................ 2-3 2.1.7 Gaps Between Members............................................................................. 2-4 2.1.8 Faying Surfaces.......................................................................................... 2-4 2.1.9 Fillet Weld Profiles (AWS 3.6)................................................................... 2-5 2.1.10 Gaps for Tubular Structures....................................................................... 2-6 2.1.11 Undersized Fillet Welds (Buildings)............................................................ 2-6 2.1.12 Stud Welding (Manual) Fillet Weld Size..................................................... 2-6 2.1.13 Skewed T-Joints ........................................................................................ 2-7 2.2 ASME/ANSI B31.1 ................................................................................... 2-7 2.2.1 Fillet Welds................................................................................................ 2-7 2.2.2 Size of Fillet Welds.................................................................................... 2-7 2.3 ASME SECTION III ................................................................................. 2-8 2.3.1 Fillet Weld Size.......................................................................................... 2-8 2.3.2 Attachments to Piping after Hydro ............................................................. 2-9 2.4 ASME/ANSI B31.3 ................................................................................... 2-9 2.4.1 Fillet Welds................................................................................................ 2-9 2.4.2 Welded Branch Connections....................................................................... 2-11 2.4.3 Reinforcing Pad or Saddle.......................................................................... 2-11 2.4.4 Nomenclature and Symbols........................................................................ 2-12
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-1 2.1 AWS D1.1 2.1.1 Effective Length The effective length of a fillet weld is the overall length of the full-size fillet, including end returns. No reduction of weld length is necessary for starts or craters, provided the weld is full size throughout its length, including craters. (AWS-2.3.2.1, 8.15.1.3) 2.1.2 Effective Throat The effective throat is the shortest distance from the root of the joint to its face. (2.3.2.4) For the purpose of measuring fillet welds, the theoretical throat should be used.
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-2 2.1.3 Theoretical Throat The distance from the beginning of the root of the joint perpendicular to the hypotenuse of the largest right triangle that can be inscribed within the fillet weld cross section. This dimension is based on the assumption that the root opening is equal to zero. (AWS A3.0)
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-3 2.1.4 Minimum Size Minimum Fillet Weld Size (Prequalified Joints) (2.7.1.1). A fillet weld in any single continuous weld shall be permitted to underrun the nominal fillet size required by 1/16 in. without correction, provided that the undersize portion of the weld does not exceed 10% of the length of the weld. On web-to-flange welds on girders, no underrun is permitted at the ends for a length equal to twice the width of the flange. (8.15.1.7) MINIMUM FILLET WELD SIZE FOR PREQUALIFIED JOINTS Base Metal Thickness of Thicker Part Jointed (T) Minimum Size of Fillet Weld* in. in. T£14 1/8 1/4<T£1/2 3/16 Single-pass 1/2<T£3/4 1/4 welds must 3/4<T 5/16 be used * Except that the weld size need not exceed the thickness of the thinner part joined: For this exception, particular care should be taken to provide sufficient preheat to ensure weld soundness. 2.1.5 Maximum Size Along Edges The maximum size fillet weld made on material less than 1/4 inch may be the thickness of the base material. (A - below.) For base material 1/4 inch and thicker, the maximum fillet weld size is 1/16 inch less than the base metal thickness (B - below.), unless the weld is designated on the drawing to be built out in order to obtain full throat thickness. However, the distance between the edge of the base metal and toe of the weld may be less than 1/16 inch, provided the edge is clearly visible and the weld size clearly verifiable. (AWS 2.7.1.2) The maximum fillet weld along edges of material shall be equal to the thickness of the base material. (AWS 10.10.4) 2.1.6 Minimum Length The minimum length of intermittent fillet welds shall be 1-1/2 inches. (AWS 2.7.1.5)
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-4 2.1.7 Gaps Between Members The parts to be joined by fillet welds shall be brought into as close contact as practicable. The gap between parts shall not exceed 3/16 in. except in cases involving either shapes or plates 3 in. greater in thickness if, after straightening and in assembly, the gap cannot be closed sufficiently to meet this tolerance. In such cases, a maximum gap of 5/16 in. is acceptable provided a sealing weld or suitable backing material is used to prevent melting through. Note: If the separation is 1/16 in. or greater, the leg of the fillet weld shall be increased by the amount of the separation or the contractor shall demonstrate that the required effective throat has been obtained. (3.3.1) 2.1.8 Faying Surfaces The separation of faying surfaces of lap joints, plug, slot welds, and butt welds using a backing ring or bar shall not exceed 1/16 inch. (AWS 3.3.1) Note: Gaps greater than mentioned above should be brought to the attention of the Engineer.
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-5 2.1.9 Fillet Weld Profiles (AWS 3.6) Desirable Fillet Weld Profiles Note: Convexity, C, of a weld or individual surface bead shall not exceed 0.07 times the actual face width of the weld or individual bead, respectively, plus 0.06 in. (1.5 mm). Acceptable Fillet Weld Profiles
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-6 Unacceptable Fillet Weld Profiles 2.1.10 Gaps for Tubular Structures Parts to be fillet welded shall have a maximum gap of 3/16 inch. If the separation is 1/16 inch or greater, the leg of the fillet weld shall be increased by the amount of the separation. Gaps greater than 3/16 inch shall be subject to the approval of the Engineer. (AWS 10.14.1) 2.1.11 Undersized Fillet Welds (Buildings) A fillet weld in any single continuous weld shall be permitted to underrun the nominal fillet size required by 1/16 inch without correction, provided that the undersize portion of the weld does not exceed 10% of the length of the weld. On web-to-flange welds on girders, no underrun is permitted at the ends for a length equal to twice the width of the flange. (AWS 8.15.1.7) 2.1.12 Stud Welding (Manual) Fillet Weld Size At the contractor’s option, studs may be fillet welded by the SMAW process, provided the requirements of 7.5.5 through 7.5.5.6 of the AWS Code are met.
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-7 MINIMUM FILLET WELD SIZE FOR SMALL DIAMETER STUDS Stud Diameter Minimum Size of Fillet in. in. 1/4 thru 7/16 3/16 1/2 1/4 5/8, 3/4, 7/8 5/16 1 3/8 Electrode Size. Welding shall be done with low hydrogen electrodes 5/32 or 3/16 in. in diameter except that a smaller diameter electrode may be used on studs 7/16 in. or less in diameter or for out-of-position welds. (7.5.5.2) Preheat. The base metal to which studs are welded shall be preheated in accordance with the requirements of Table 4.2 of Section 13 in -this handbook. (7.5.5.5) 2.1.13 Skewed T-Joints Fillet welds may be used in skewed T-joints having a dihedral angle of not less than 60 degrees nor more than 135 degrees. Angles smaller than 60 degrees are permitted; however, in such cases, the weld is considered to be a partial penetration groove weld. (2.7.1.4) For additional information concerning skewed T-joints, refer to Section 16 of this handbook. 2.2 ANSI B31.1 2.2.1 Fillet Welds In making fillet welds, the weld metal shall be deposited in such a way as to secure adequate penetration into the base metal at the root of the weld. (127.4.4) 2.2.2 Size of Fillet Welds Fillet welds may vary from convex to concave. The size of a fillet is determined as shown below. (127.4.4) Note: Excessive convexity of fillet welds is not a criterion for rejection.
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-8 Figure 127.4.4(A) Notes: (1) The “size” of an equal leg fillet weld is the leg length of the largest inscribed right isosceles triangle. Theoretical throat = 0.7 x size. (2) For unequal leg fillet welds, the “size” of the weld shall be described using both leg lengths and their location on the members being joined. (3) Fillet welds between members which lie at angles other than 90 degrees shall be described as in Notes (1) and (2). (4) For all fillet welds the theoretical throat shall be determined by calculation based on the angle between surfaces to be welded and the specified leg lengths. (5) For all fillet welds the leg dimensions and theoretical throat dimensions shall lie within the cross section of the deposited weld metal as shown in the sketches. 2.3 ASME SECTION III 2.3.1 Fillet Weld Size Shape and size of fillet welds may vary from convex to concave. The size of the weld shall be in accordance with the figure below (NX-4427).
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-9 2.3.2 Attachments to Piping after Hydro Attachments may be made by fillet welds to a piping system after performance of a pressure test, provided the welds do not exceed 3/8 inch throat thickness and do not exceed a total length of 24 inches (NX-4436) 2.4 ASME B31.3 2.4.1 Fillet Welds Fillet welds (including socket welds) may vary from convex to concave. The size of a fillet weld is determined as shown in Fig. 328.5.2A. (a) Typical weld details for slip on and socket welding flanges are shown in Fig. 328.5.2B; minimum welding dimensions for other socket welding components are shown in Fig. 328.5.2C. (b) If slip-on flanges are single welded, the weld shall be at the hub.
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-10
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-11 2.4.2 Welded Branch Connections Welded branch connections (including integrally reinforced proprietary branch connection fittings) which abut the outside of the run or which are inserted in an opening in the run shall be attached by fully penetrated groove welds. (a) The welds shall be finished with cover fillet welds having a throat dimension not less than tc. See Fig. 328.5.4D sketches (1) and (2). 2.4.3 Reinforcing Pad or Saddle A reinforcing pad or saddle shall be attached to the branch pipe by either: (1) a fully penetrated groove weld finished with a cover fillet weld having a throat dimension not less than tc or (2) a fillet weld having a throat dimension not less than 0.7t min. See Fig. 328.5.4D sketch (5). (3) The outer edge of a reinforcing pad or saddle shall be attached to the run pipe by a fillet weld having a throat dimension not less than 0.5**Tr .. See Fig.328.5.4D Sketches (3), (4), and (5).
Section 2 Measurement of Fillet Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter02.doc Welding Inspection Handbook 2-12 2.4.4 Nomenclature and Symbols The nomenclature and symbols used herein and in Fig. 328.5.4D are: tc = lesser of 0.7 Tb or 1/4 in. Tb = nominal thickness of branch Th = nominal thickness of header Tr = nominal thickness of reinforcing pad or saddle tmin = lesser of Tb or Tr
Section 3 Use of Inspection Gages \\houw33883\sstaffor$\temporary\welding inspection\chapter03.doc Welding Inspection Handbook 3-0 Page 3.1 CAMBRIDGE INSPECTION GAGE .............................................................................. 3-1 3.1.1 Cambridge Inspection Gage............................................................................................. 3-1 3.1.2 Material Thickness.......................................................................................................... 3-1 3.1.3 Bevel Angle..................................................................................................................... 3-1 3.1.4 External Misalignment .................................................................................................... 3-2 3.1.5 Pit Gage........................................................................................................................... 3-2 3.1.6 Fillet Welds..................................................................................................................... 3-3 3.2 FIBRE METAL FILLET WELD GAGE.......................................................................... 3-4 3.2.1 Fibre Metal Weld Gage.................................................................................................... 3-4 3.2.2 Leg Size .......................................................................................................................... 3-4 3.2.3 Theoretical Throat........................................................................................................... 3-5 3.3 FILLET WELD GAGE.................................................................................................... 3-6 3.3.1 Leg Size and Throat ........................................................................................................ 3-6 3.3.2 Butt Weld Reinforcement................................................................................................. 3-7 3.4 G.A.L. HI LO GAGE....................................................................................................... 3-7 3.4.1 G.A.L. Hi Lo Gage .......................................................................................................... 3-7 3.4.2 Misalignment/Thickness.................................................................................................. 3-7 3.4.3 Fillet Weld Leg Measurement/Butt Weld Reinforcement.................................................. 3-8 3.5 OLD M&QS WELD GAGE............................................................................................. 3-8 3.5.1 Old M&QS Weld Gage.................................................................................................... 3-8 3.5.2 Leg Size of Fillet at 90° Angle......................................................................................... 3-9 3.5.3 "W" Dimension for Skew T Fillets (Acute Side)............................................................... 3-9 3.5.4 "W" Dimension for Skew T Fillets (Obtuse Side)............................................................. 3-9
Section 3 Use of Inspection Gages \\houw33883\sstaffor$\temporary\welding inspection\chapter03.doc Welding Inspection Handbook 3-1 3.1 CAMBRIDGE INSPECTION GAGE 3.1.1 Cambridge Inspection Gage The Cambridge Inspection Gage may be used for material thickness, bevel angle, misalignment, fillet weld measurements, etc. The following illustrations show how this gage is used. 3.1.2 Material Thickness Edge “A” slides inside the pipe or on the bottom of the plate, making sure good contact is made along its length. Slide “B” is pushed down to make contact with the outside diameter of the pipe, or top of the plate, and the thickness is read from Scale “C”. 3.1.3 Bevel Angle Edge “A” lays along the top of the pipe or plate. Slide “B” is pushed down across the bevel, and Scale “C” indicates the bevel angle.
Section 3 Use of Inspection Gages \\houw33883\sstaffor$\temporary\welding inspection\chapter03.doc Welding Inspection Handbook 3-2 3.1.4 External Misalignment Edge “A” lays flat on the high member. Slide “B” is pushed down to contact the low member and Scale “C” indicates the amount of external misalignment. 3.1.5 Pit Gage Edge “A” lays along the pipe or plate being checked. The point of Slide “B” is centered over the pit or undercut and pushed in, making sure Edge “A” keeps in contact with plate or pipe. Scale “C” gives you the depth of the pits or undercut.
Section 3 Use of Inspection Gages \\houw33883\sstaffor$\temporary\welding inspection\chapter03.doc Welding Inspection Handbook 3-3 3.1.6 Fillet Welds Fillet welds can be measured with this gage, but it is recommended that the Fibre Metal product gages be used for fillet weld measurements. However, if Fibre Metal gages are not available, the Cambridge gage may be used as shown below. Leg Size Theoretical Throat
Section 3 Use of Inspection Gages \\houw33883\sstaffor$\temporary\welding inspection\chapter03.doc Welding Inspection Handbook 3-4 3.2 FIBRE METAL FILLET WELD GAGE 3.2.1 Fibre Metal Weld Gage The following sketches illustrate the correct use of the Fibre Metal Product weld inspection gages used for fillet weld inspection. 3.2.2 Leg Size Acceptable Leg Size Unacceptable Leg Size
Section 3 Use of Inspection Gages \\houw33883\sstaffor$\temporary\welding inspection\chapter03.doc Welding Inspection Handbook 3-5 3.2.3 Theoretical Throat Acceptable Throat Unacceptable Throat
Section 3 Use of Inspection Gages \\houw33883\sstaffor$\temporary\welding inspection\chapter03.doc Welding Inspection Handbook 3-6 3.3 FILLET WELD GAGE 3.3.1 Leg Size and Throat This gage is used to measure leg size and throat size of convex or concave fillet welds, and the reinforcement of butt welds. The following illustrations indicate how this gage is used. Fillet Weld Leg Size Throat of a Convex or Concave Fillet
Section 3 Use of Inspection Gages \\houw33883\sstaffor$\temporary\welding inspection\chapter03.doc Welding Inspection Handbook 3-7 3.3.2 Reinforcement of Butt Welds 3.4 G.A.L. HI LO GAGE 3.4.1 G.A.L. Hi Lo Gage The G.A.L. Hi Lo Gage may be used for material thickness, misalignment, included bevel angle, fillet weld leg, measuring scribe lines on socket welds, etc. The illustrations below show some of the uses of this gage. 3.4.2 Misalignment/Thickness For internal misalignment, the gage is turned 90° and Area A is inserted into the gap. When turned back 90°, the handles (b) are pulled tight and the slide (C) is pushed down square against the outer surface. At this point, the set screw (D) is set and the internal misalignment is read at Area B. Material thickness is read in the slide scale (E).
Section 3 Use of Inspection Gages \\houw33883\sstaffor$\temporary\welding inspection\chapter03.doc Welding Inspection Handbook 3-8 3.4.3 Fillet Weld Leg Measurement/Butt Weld Reinforcement For fillet leg measurement, one of the handles is placed against the flat surface and the other is raised to the top of the fillet and the scale is read. Butt weld reinforcement is completed in the same manner. 3.5 OLD M&QS WELD GAGE 3.5.1 Old M&QS Weld Gage The old M&QS gage(developed in 1983) may be used for measuring all types of fillet welds misalignment, material thickness, etc. The gage is always read in the same manner. The bottom of the gage is placed on a flat surface and the arm placed on the top of the article to be measured. For the thickness or size of the article, the dimension is taken directly from the scale at the top of the arm. The following instructions show some of the ways this gage is used.
Section 3 Use of Inspection Gages \\houw33883\sstaffor$\temporary\welding inspection\chapter03.doc Welding Inspection Handbook 3-9 3.5.2 Leg Size of a Fillet at 90° Angle 3.5.3 “W” Dimension For Skew T Fillets (Acute Side) 3.5.4 “W” Dimension For Skew T Fillets (Obtuse Side)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-0 Page 4.1 AWS D1.1 (GENERAL............................................................................. 4-1 4.1.1 Effective Area ............................................................................................ 4-1 4.1.2 Weld Size (Complete Penetration).............................................................. 4-1 4.1.3 Weld Size (Partial Penetration)................................................................... 4-1 4.1.4 Effective Weld Size (Flare Groove)............................................................ 4-1 4.1.5 Weld Size (Minimum) ................................................................................ 4-2 4.1.6 Assembly Tolerances (Partial Penetration).................................................. 4-2 4.1.7 Alignment (Butt Joints).............................................................................. 4-3 4.1.8 Assembly Tolerances.................................................................................. 4-3 4.1.9 Wider Permitted Root Openings................................................................. 4-4 4.1.10 Tack Welds................................................................................................ 4-5 4.1.11 Reinforcement............................................................................................ 4-5 4.1.12 Flush or Less.............................................................................................. 4-5 4.1.13 Ends of Butt Joints..................................................................................... 4-6 4.2 STATICALLY LOADED STRUCTURES ................................................ 4-7 4.2.1 Transition Thickness “Unequal” ................................................................. 4-7 4.2.2 Temporary Welds....................................................................................... 4-8 4.2.3 Backing Strips............................................................................................ 4-8 4.2.4 Backing Material........................................................................................ 4-8 4.3 TUBULAR STRUCTURES....................................................................... 4-9 4.3.1 Special Provisions...................................................................................... 4-9 4.3.2 Root Opening............................................................................................. 4-9 4.3.3 Temporary Welds....................................................................................... 4-9 4.4 ASME SECTION III ................................................................................. 4-9 4.4.1 Alignment Requirements............................................................................ 4-9 4.4.2 Fairing of Offsets – Applicable Only to Joints Welded from Two Sides....... 4-11 4.4.3 Welding From One Side (Inside Inaccessible)............................................. 4-12 4.4.4 Fairing of Offsets – For Welds Made From One Side.................................. 4-13
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-0a Page 4.4.5 Longitudinal Joints – Tolerances................................................................ 4-13 4.4.6 Weld Joint Reinforcement for Vessels, Pumps, and Valves......................... 4-13 4.4.7 Reinforcement for Piping............................................................................ 4-13 4.4.8 Weld Surfaces............................................................................................ 4-14 4.4.9 Welding End Transitions............................................................................ 4-14 4.4.10 Backing Rings – Piping .............................................................................. 4-15 4.5 ASME B31.1 ............................................................................................. 4-17 4.5.1 Backing Rings............................................................................................ 4-17 4.5.2 End Preparations........................................................................................ 4-17 4.5.3 Girth Butt Welds........................................................................................ 4-18 4.5.4 Longitudinal Butt Welds ............................................................................ 4-20 4.6 ASME B31.3 ............................................................................................. 4-22 4.6.1 Backing Rings............................................................................................ 4-22 4.6.2 End Preparations........................................................................................ 4-22 4.6.3 Alignment .................................................................................................. 4-23
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-1 4.1 AWS D1.1 (GENERAL) 4.1.1 Effective Area The effective area shall be the effective weld length multiplied by the weld size. (2.3.2) 4.1.2 Weld Size (Complete Penetration) The weld size of a complete joint penetration groove weld shall be the thickness of the thinner part joined. No increase in the effective area for design calculation is permitted for weld reinforcement. (2.3.4.1) 4.1.3 Weld Size (Partial Penetration) The weld size for partial penetration groove weld is that shown in Chapter 15 unless specifically qualified otherwise. 4.1.4 Effective Weld Size (Flare Groove) The effective weld size of flare bevel groove welds when-filled flush to the surface of a round bar, a 90° bend in a formed section, or a rectangular tube shall be as shown in Table 2.1 unless a larger size has been demonstrated by qualification as outlined below. (2.3.3.2) Table 2.1 Effective Weld Sizes of Flare Groove Welds Flare-Bevel Groove Welds Flare-V-Groove Welds 5/16 R 1/2 R* Note: R = radius of outside surface * Except 3/8 R for GMAW (except short circuiting transfer) process when R is 1/2 in. or greater 1) When required by the Engineer, test sections shall be used to verify that the effective throat is consistently obtained. 2) For a given set of WPS conditions, if the contractor has demonstrated consistent production of larger effective weld sizes than those show in Table 2.1, the contractor may establish such larger effective weld sizes by qualification. 3) Qualification required by (2) shall consist of sectioning the radiused member, normal to its axis, at midlength and ends of the weld. Such sectioning shall be made on a number of combinations of material sizes representative of the range used by the contractor in construction or as required by the Engineer. (4.10.5)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-2 4.1.5 Weld Size (Minimum) The minimum weld size of pre-qualified partial joint penetration single-, or double-V, bevel-, and U-, groove welds shall be as in Table 3.4. The PJP square butt weld B-P1 and flare-bevel groove weld BTC-P10 minimum weld sizes are to be calculated from the figures in Chapter 15. (3.12.2.1) Table 3.4 Minimum Prequalified Weld Sizes for Partial Joint Penetration Groove Welds Base Metal Thickness of Thicker Part Joined Minimum Effective Throat* in. in. 1/8 to 3/16 incl. 1/16 Over 3/16 to 1/4 incl. 1/8 Over 1/4 to 1/2 incl. 3/16 Over 1/2 to 3/4 incl. 1/4 Over 3/4 to 1-1/2 incl. 5/16 Over 1-1/2 to 2-1/4 incl. 3/8 Over 2-1/4 to 6 incl. 1/2 Over 6 5/8 * Except the effective throat need not exceed the thickness of the thinner part. 4.1.6 Assembly Tolerances (Partial Penetration) The parts to be joined by partial joint penetration groove welds made parallel to the length of the member shall be brought into as close contact as practicable. The root opening between parts shall not exceed 3/16 in. except in cases involving rolled shapes or plates 3 inches or greater in thickness if, after straightening and assembly, the root cannot be closed sufficiently to meet this tolerance. In such cases, a maximum root opening of 5/16 inch is acceptable, provided suitable backing material (see Note) is used and the final weld meets the requirements for weld size. Tolerances for bearing joints shall be in accordance with the applicable contract specifications. (5.22.2) Note: Backing to prevent melting-through may be of copper, flux, glass tape, ceramic, iron powder, or similar materials; by means of shielded metal arc welding root passes deposited with low hydrogen electrodes, or other arc welding processes.
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-3 4.1.7 Alignment (Butt Joints) Parts to be joined at butt joints shall be carefully aligned. Where parts are effectively restrained against bending due to eccentricity in alignment, an offset not exceeding 10 percent of the thickness of the thinner part joined, but in no case is more than 1/8 inch, shall be permitted as a departure from the theoretical alignment. See Figure 5.3. In correcting misalignment in such cases, the parts shall not be drawn in to a greater slope than 1/2 in. in 12 in. Measurement of offset shall be based upon the centerline of the parts unless otherwise shown on the drawings. See Figure C5.4. (5.22.3) Figure C5.3 – Permissible Offset in Abutting Members. Figure C5.4 4.1.8 Assembly Tolerances With the exclusion of electroslag and electrogas welding and with exception of 5.22.4.3 for root openings in excess of those permitted in Figure 5.3, the dimensions of the cross section of the groove welded joints which vary from those shown on the detail drawings by more than the following tolerances shall be referred to the Engineer for approval or correction. (5.22.4.1)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-4 Root Not Gouged* Root Gouged in. in. (1) Root face of joint ± 1/16 Not limited (2) Root opening of joints ± 1/16 + 1/16 without steel backing - 1/8 Root opening of joints + 1/4 Not with steel backing - 1/16 applicable (3) Groove angle of joint + 10° + 10°. - 5° - 5° * See 5.2.4.2 for tolerances for complete joint penetration tubular groove welds made from one side without backing. Figure 5.3 – Workmanship Tolerances in Assembly of Groove Welded Butt Joints 4.1.9 Wider Permitted Root Openings Root openings wider than those permitted in 5.22.4.1, but not greater than twice the thickness of the thinner part or 3/4 in., whichever is less, may be corrected by welding to acceptable dimensions prior to joining the parts by welding. (5.22.4.3) Root openings larger than those shown in 5.22.4.1, may be corrected by welding only with the approval of the Engineer. (5.22.4.4)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-5 4.1.10 Tack Welds Tack welds shall be subject to the same requirements as the final welds except that: (1) Preheat is not mandatory for single-pass tack welds which are remelted and incorporated into continuous submerged arc welds. (2) Discontinuities such as undercut, unfilled craters, and porosity need not be removed before the final submerged arc welding. (5.18.2) Tack welds which are incorporated into the final weld shall be made with electrodes meeting the requirements of the final welds and shall be cleaned thoroughly. Multiple-pass tack welds shall have cascaded ends. (5.18.2.1) Tack welds not incorporated into final welds shall be removed, except that for statically loaded structures, they need not be removed unless required by the Engineer. (5.18.2) 4.1.11 Reinforcement Groove welds shall be made with minimum face reinforcement unless otherwise specified. In the case of butt and corner joints, the reinforcement shall not exceed 1/8 inch in height. All welds shall have a gradual transition to the plane of the base-meal surfaces with transition areas free of undercut except as permitted by this code. Figure 5.4(D) shows typically acceptable groove weld profiles in butt joints. Figure 5.4(E) shows typically unacceptable weld profiles for groove butt joints. (5.24.4) 4.1.12 Flush or Less Surfaces of butt joints required to be flush shall be finished so as not to reduce the thickness of the thinner base metal or weld metal by more than 1/32 inch or 5% of the thickness, whichever is less. Remaining reinforcement shall not exceed 1/32 inch in height. However, all reinforcement shall be removed where the weld forms part of a faying or contact surface. All reinforcements shall blend smoothly into the plate surfaces with transition areas free from undercut. (5.24.4.1)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-6 4.1.13 Ends of Butt Joints Ends of butt joints required to be flush shall be finished so as not to reduce the width beyond the detailed width or the actual width furnished, whichever is greater, by more than 1/8 inch or so as not to leave reinforcement at each end that exceeds 1/8 inch. Ends of welded butt joints shall be fared at a slope not to exceed 1 in 10. (5.31.4) Figure 5.4 (D, E) Groove Weld Profiles
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-7 4.2 STATICALLY LOADED STRUCTURES 4.2.1 Transition Thickness “Unequal” See Figure 2.6. Figure 2.6 – Transition of Butt Joints in Parts of Unequal Thickness (Nontubular)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-8 4.2.2 Temporary Welds Temporary welds shall be subject to the same welding procedure requirements as the final weld. These shall be removed, when required by the Engineer. When they are removed, the surface shall be made flush with the original surface. (5.18.1) 4.2.3 Backing Strips Steel backing of welds used in statically loaded structures need not be welded full length and need not be removed, unless required by the Engineer. (5.10.5) 4.2.4 Backing Material Roots of groove welds may be backed by copper, flux, glass tape, ceramic, iron powder, or similar materials to prevent melting through. They may also may be sealed by means of root passes deposited with low hydrogen electrodes if SMAW is used, or by other arc welding processes. (5.10) Groove welds made with the use of steel backing shall have the weld metal thoroughly fused with the backing. (5.10.1) Steel backing shall be made continuous for the full length of the weld. All necessary joints in the steel backing shall be complete joint penetration welds in butt joints meeting all the requirements of Section 5 of AWS Dl.l. (5.10.2) Weld tabs used in welding shall conform to the following requirements: (1) When used in welding with an approved steel listed in Table 3.1 or Annex M, they may be any of the steels listed in Table 3.1 or Annex M. (2) When used in welding with a steel qualified in accordance with 4.7.3 they may be (a) The steel qualified, or (b) Any steel listed in Table 3.1 or Annex M. Steel for backing shall conform to the requirements of (1) and (2), except that 100 ksi minimum yield strength steel as backing shall only be used with 100 ksi minimum yield strength steel. Spacers used shall be of the same material as the base metal. (5.2.2)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-9 4.3 TUBULAR STRUCTURES 4.3.1 Special Provisions Special provisions for joints, processes, procedures, and welder requirements are contained in 4.12, 4.13, and 4.26 of AWS D1.1. The details of the transition of thickness of tubular joint of unequal thickness are shown in Figure 2.4. 4.3.2 Root Opening Joint requirements for groove welds, from those shown on the detailed drawings, should be in accordance with paragraph 4.1.8 (AWS 5.22.4). In addition, the following tolerances will apply to complete joint penetration welds made from one side only without backing. (5.22.4) Root Face of Joint Root Opening of Joints Without Steel Backing* Groove Angle of Joint in. mm in. mm deg. SMAW ± 1/16 1.6 ± 1/16 1.6 ±5 GMAW ± 1/32 0.8 ± 1/16 1.6 ±5 FCAW ± 1/16 1.6 ± 1/16 1.6 ±5 * Root openings wider than permitted by the above tolerances but not greater than the thickness of the thinner part may be built up by welding to acceptable dimensions prior to the joining of the parts by welding. 4.3.3 Temporary Welds Temporary welds shall be subject to the same welding procedure requirements as the final weld. These shall be removed, when required by the Engineer. When they are removed, the surface shall be made flush with the original surface. (5.18.1) 4.4 ASME SECTION III 4.4.1 Alignment Requirements Welding From Two Sides (a) Alignment of sections which are welded from two sides shall be such that the maximum offset of the finished weld will not be greater than the applicable amount listed in Table NB, NE-4232-1 or Table NC, ND, -4232(a)-1 as applicable, where t is the nominal thickness of the thinner section at the joint.
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-10 Figure 2.4 Transition of Thickness of Butt Joints in Parts of Unequal Thickness (Tubular) (see 2.41)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-11 Table NB, NE-4232-1 and Table NC, ND -4232(a)-1 Maximum Allowable Offset in Final Welded Joints Direction of Joints Section Thickness, in. Longitudinal Circumferential Up to 1/2, incl. 1/4 t 1/4 t Over 1/2 to 3/4, incl. 1/8 in. 1/4 t Over 3/4 to 1-1/2, incl. 1/8 in. 3/16 in. Over 1-1/2 to 2, incl. 1/8 in. 1/8 t Over 2 Lesser of 1/16 t or 3/8 in. Lesser of 1/8 t or 3/4 in. For component supports (NF) the maximum allowable offset is given in Table NF-4232-1. Table NF-4232-1 Maximum Allowable Offset in Final Butt Welded Joints Section Thickness, in. Maximum Allowable Offset Up to 3/4, incl. 1/4 t Over 3/4 to 1-1/2, incl. 3/16 in. Over 1-1/2 to 2, incl. 1/8 t Over 2 Lesser of 1/8 t or 3/4 in. (b) Joints in spherical vessels, joints within heads, and joints between cylindrical shells and hemispherical heads shall meet the requirements for longitudinal joints. 4.4.2 Fairing of Offsets – Applicable Only to Joints Welded from Two Sides (a) Class 2 and 3 Any offset within the allowable tolerance provided above shall be faired to at least a 3:1 taper over the width of the finished weld or, if necessary, by adding additional weld metal beyond what would otherwise be the edge of the weld. (NB, NC, ND-4232.1) (b) Class 1 and MC In addition to (a) above: In addition, offsets greater than those stated in Table NB, NE-4232-1 are acceptable provided the requirements of NB, NE-3200 are met. (NB, NE-4232.1) (c) Component Supports Any offset within the allowable tolerance of Table NF-4232-1 shall be blended uniformly over the width of the finished weld or, if necessary, by adding additional weld metal beyond what would otherwise be the edge of the weld. (NF-4232.1)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-12 4.4.3 Welding From One Side (Inside Inaccessible) Circumferential Joints - Tolerances Class 1, 2 and 3 Figure NX-4233-1 Should tolerances on diameter, wall thickness, out-of-roundness, etc., result in inside diameter variations which do not meet these limits, the inside diameters shall be counterbored, sized, or ground to produce a bore within these limits provided the requirements of NX-4250 are met.
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-13 4.4.4 Fairing of Offsets – For Welds Made From One Side Offset of outside surfaces shall be faired to at least a 3:1 taper over the width of the finished weld or, if necessary, by adding additional weld metal. (NB, NC, ND-4233) 4.4.5 Longitudinal Joints – Tolerances For longitudinal joints the misalignment of inside surfaces shall not exceed 3/32 inch and the offset of outside surfaces shall be faired to at least a 3:1 taper over the width of the finished weld or, if necessary, by adding additional weld metal. (NB, NC, ND-4233) 4.4.6 Weld Joint Reinforcement for Vessels, Pumps, and Valves The surface of the reinforcement of all butt welded joints in vessels, pumps, and valves may be flush with the base material or may have uniform crowns. The height of reinforcement on each face of the weld shall not exceed the thickness in the following tabulation. (NX-4426) Nominal Thickness, in. Maximum Reinforcement, in. Up to 1, incl. 3/32 Over 1 to 2, incl. 1/8 Over 2 to 3, incl. 5/32 Over 3 to 4, incl. 7/32 Over 4 to 5, incl. 1/4 Over 5 5/16 4.4.7 Reinforcement for Piping For double welded butt joints, the limitation on the reinforcement given in Column 1 of the following tabulation shall apply separately to both inside and outside surfaces of the joint. For single welded butt joints, the reinforcement given in Column 2 shall apply to the inside surface and the reinforcement given in Column I shall apply to the outside surface. The reinforcement shall be determined from the higher of the abutting surfaces involved. (NX-4426.2) Maximum Reinforcement Thickness, in. Material Nominal Thickness, in. Column 1 Column 2 Up to 1/8, incl. 3/32 3/32 Over 1/8 to 3/16, incl. 1/8 3/32 Over 3/16 to 1/2, incl. 5/32 1/8 Over 1/2 to 1, incl. 3/16 5/32 Over 1 to 2, incl. 1/4 5/32 Over 2 Greater of 1/4 in. or 1/8 times the width of the weld, in inches
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-14 4.4.8 Weld Surfaces The surface of the welds shall be sufficiently free from coarse ripples, grooves, overlaps, and abrupt ridges and valleys to meet (a) through (e) below. (a) The surface condition of the finished weld shall be suitable for the proper interpretation of radiographic and other required nondestructive examinations of the weld. In those cases where there is a question regarding the surface condition of the weld on the interpretation of a radiographic film, the film shall be compared to the actual weld surface for interpretation and determination of acceptability. (b) Reinforcements shall be within the tolerances given above. (c) Undercuts shall not exceed 1/32 inch and shall not encroach on the required section thickness. (d) Concavity on the root side of a single welded circumferential butt weld is permitted when the resulting thickness of the weld meets the requirements of NX 3000. (NX-4424) (e) If grinding is required to meet the above criteria, care shall be taken to avoid reducing the weld or base metal below the required thickness. 4.4.9 Welding End Transitions
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-15 General Notes: (a) Weld bevel is shown for illustration only (b) The weld reinforcement permitted by NX-4426 may lie outside the maximum envelope Notes: (1) The value of t min. is whichever is applicable: (a) the minimum ordered wall thickness of the pipe (b) the 0.875 times the nominal wall thickness of pipe ordered to a pipe schedule wall thickness which has an under tolerance of 12.5% (c) the minimum ordered wall thickness of the cylindrical welding end of a component or fitting (or the thinner of the two) when the joint is between two components (2) The maximum thickness at the end of the component is: (a) the greater of (t min. +0.15 in.) or 1.15 t min. when ordered on a minimum wall basis (b) the greater of (t min. +0.15 in.) or 1.10 t nom. when ordered on a nominal wall basis The welding ends of items shall provide gradual change in thickness from the item to the adjoining item. Any welding end transition which lies entirely within the envelope shown in Figure NX4250-1 is acceptable, provided that: (a) the wall thickness in the transition region is not less than the min. wall thickness of the adjoining item; and (b) sharp reentrant angles and abrupt changes in slope in the transition region are avoided. When the included angle between any two adjoining surfaces of a taper transition is less than 150°, the intersection or corner (except for the weld reinforcement) shall be provided with a radius of at least 0.05tmin. 4.4.10 Backing Rings – Piping (a) Class 1 When used in components other than piping, backing rings shall conform to the requirements of NB-4240. Backing rings shall not be used in piping unless removed after welding and the inside surfaces of the roots are examined by a magnetic particle or liquid penetrant method, in accordance with NB-5110, and meeting the acceptance standards of NB-5340 or NB-5350. The material for backing rings, when used, shall be compatible with the base metal. Permanent backing rings, when permitted by NB-3352, shall be continuous, and any splices shall be made by full penetration welds. Spacer pins shall not be incorporated into the welds. (NB-4421)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-16 (b) Class 2 Backing rings which remain in place may be used for piping in accordance with the requirements of NC-3661.2. The materials for backing rings shall be compatible with the base metal but spacer pins shall not be incorporated into the weld. (NC-4421) (c) Class 3 Backup plates and backing rings which remain in place, and compression rings or stiffeners of storage tanks such as angles, bars, and ring girders may be used. Their materials shall be compatible with the base metal, but spacer pins shall not be incorporated into the welds. (ND-4421) (d) Class MC Backing rings shall conform to the requirements of NE-4240. The material for backing rings, when used, shall be compatible with the base metal. Permanent backing rings, when permitted by NE-4240, shall be continuous, and any splices shall be made by full penetration welds. Spacer pins shall not be incorporated into the welds. (NE-4421) (e) Component Supports The material for backing strips, when used, shall be compatible with the base metal. (NF-4421)
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-17 4.5 ASME B31.1 4.5.1 Backing Rings Backing rings, when used, shall conform to the following requirements: (A) Ferrous Rings. Ferrous metal backing rings which become a permanent part of the weld shall be made from material of weldable quality, compatible with the base material and the sulfur content shall not exceed 0.05%. (A.1) Backing rings may be of the continuous machined or split band type. (A.2) If two abutting surfaces are to be welded to a third member used as a backing ring and one or two of the three members are ferritic and the other member or members are austenitic, the satisfactory use of such materials shall be determined by the welding procedure qualified as required in paragraph 127.5. (A.3) Backing strips used at longitudinal welded joints shall be removed. (B) Nonferrous and Nonmetallic Rings. Backing rings of nonferrous or nonmetallic materials may be used for backing provided they are included in a welding procedure qualified as required in paragraph 127.5. Nonmetallic or nonfusing rings shall be removed. (127.2.2) 4.5.2 End Preparations (A.1) Oxygen or arc cutting is acceptable only if the cut is reasonably smooth and true, and all slag is cleaned from the flame cut surfaces. Discoloration which may remain on the flame cut surface is not considered to be detrimental oxidation. (A.2) Butt-welding end preparation dimensions contained in ANSI B16.25 or any other end preparation which meets the procedure qualification are acceptable. (A.3) If piping component ends are bored, such boring shall not result in the finished wall thickness after welding less than the minimum design thickness. Where necessary, weld metal of the appropriate analysis may be deposited on the inside or outside of the piping component to provide sufficient material for machining to insure satisfactory fitting of rings. (A.4) If the piping component ends are upset, they may be bored to allow for a completely recessed backing ring, provided the remaining net thickness of the finished ends is not less than-the minimum design thickness. (B) Cleaning. Surfaces for welding shall be clean and shall be free from paint, oil, rust, scale, or other material which is detrimental to welding.
Section 4 Groove Welds \\houw33883\sstaffor$\temporary\welding inspection\chapter04.doc Welding Inspection Handbook 4-18 (C) Alignment. The inside diameters of piping components to be joined shall be aligned as accurately as is practicable within existing commercial tolerances on diameters, wall thicknesses, and out-of-roundness. Alignment shall be preserved during welding. The internal misalignment shall not exceed 1/16 in. unless the piping design specifically states a different allowable misalignment. When the internal misalignment exceeds the allowable, it is preferred that the component with the wall extending internally be internally trimmed per Figure 127.3.1. However, trimming shall result in a piping component wall thickness not less than the minimum design thickness and the change in contour shall not exceed 30 degrees. (D) Spacing. The root opening of the joint shall be as given in the Welding Procedure Specifications. (127.3) Figure 127.3.1 – Butt Welding of Piping Components with Internal Misalignment 4.5.3 Girth Butt Welds (A) Girth butt welds shall be complete penetration welds and shall be made with a single vee, double vee, or other suitable type of groove, with or without backing rings or consumable inserts The depth of the weld measured between the inside surface of the weld preparation and the outside surface of the pipe shall not be less than the minimum thickness required by Chapter II for the particular size and wall of pipe used. (B) In order to avoid abrupt transitions in the contour of the finished weld, the requirements of (B.1 through (B.4) below shall be met. (B.1) When components with different outside diameters are welded together, the welding end of the larger diameter component shall fall within the envelope defined by the solid lines in Figure 127.4.2. The weld shall form a gradual transitionnot exceeding a slopre of 30°, from the smaller to the larger component. This condition may be met by adding weld filler metal, if Necessary, beyond what would otherwise be the edge of the weld.